First published in Cleantech magazine, February 2011. Copyright Cleantech Investor 2011
By Mel Poluck
It is estimated that geothermal power from the south west of England alone could meet 2% of the UK’s annual electricity demand. Two companies are gearing up to tap Cornwall’s extensive potential resources of deep geothermal energy and look set to convert the English county into a hot spot for enhanced geothermal systems.
Traditional geothermal energy is derived by pumping naturally occurring hot water from underground to the surface. Enhanced geothermal systems (EGS) manufacture geothermal resources by creating similar conditions to traditional geothermal energy in hot dry rocks. This is achieved by pumping high pressure cold water down into rocks at depths of around three miles (five kilometres). The rock then fractures, allowing the water to circulate and heat up – and subsequently re-emerge from a second borehole as very hot water to be converted into electricity.
Cornwall was the location for Europe’s first deep geothermal R&D initiative, the Hot Dry Rock (HDR) project, which took place in Rosemanowes. Triggered by the 1973 Middle East oil crisis and subsequent search for alternative energy sources, Cornwall was identified because its geothermal resources are large: the geothermal gradient (i.e. the temperature increase with depth) is higher than elsewhere in the UK (see chart).
Knowledge gained from the Rosemanowes project, on the behaviour of rocks at significant depths, has been applied by geothermal experts across the globe ever since. After the project was disbanded in 1991, its scientists and engineers took off to apply their technical and geological knowledge to the European Enhanced Geothermal Systems Project which integrated all European EGS research activity and established a pilot EGS plant at Soultz-sur-Forêts, France. Soultz-sur-Forêts was the springboard for Europe’s first commercial EGS plant, in Landau, Germany.
Although the UK geothermal story seemed to end with the disbanding of Rosemanowes, the UK is still perceived as a pioneer. Ryan Law, Managing Director of Geothermal Energy Ltd (GEL) believes that: “The UK is still seen as a groundbreaker because of that project. People have a lot of faith in it.”
According to Law: “Geothermal is coming back home to the UK”. GEL has received planning permission to mine for hot rock energy in Cornwall and create the UK’s first commercial-scale plant to generate some 55MW of heat for local use and 10MW of electricity for the grid.
Heat will initially be drawn from a J-shaped well up to five kilometres deep, the deepest geothermal well in the UK. If successful, two more wells will be built, pumping water down to rocks that are naturally at 200°C, where most of the water turns to steam. This will then be pumped back to the surface and converted into electricity using a steam turbine. When cool, the water can be reused to produce further geothermal energy. “The stress
regime – the nature of the pressure on the rock at those depths – is key to making the system work well,” Law explains.
The plant is expected to be operational in 2013 and will cost £40 million, financed potentially by a mix of Department of Energy and Climate Change (DECC) funding, private investment and the European Regional Development Fund.
So what has sparked this renewed interest in geothermal power? “As an industry we’ve become more coherent in the UK,” says Law. “There’s the Renewable Energy Association’s Deep Geothermal Sector group. Instead of individually lobbying, it helps us get to the right ‘ears’.
And the UK Government does not want to appear to be late to the party. “At the moment we are lagging behind,” says Law. In particular, Germany and the US – where the Government recently made $330 million available for the exploration of geothermal – are years ahead of the UK.
But momentum is gathering. In 2009, the DECC made £6 million of funding available over two years for geothermal plants generating between 5-10MW. The first round of funding, some £4 million, focused on deep geothermal and supported two Cornwall-based projects, of which GEL was one.
The other Cornish company to receive funding from the UK Government was EGS Energy, which is hatching plans for a 4MW plant at the Eden Project. EGS Energy aims to drill two wells up to 4.5 kilometres deep (almost 3 miles) and use hot rock mass to produce heat and electricity at the surface to power the famous conservation centre. Water will be pumped down into one well and returned through the other, heated up by contact with the hot rock. The excess electricity will be supplied to the grid and possibly also to businesses and homes.
“We’re bringing geothermal back to Cornwall. Private investors and people in the DECC that had to be won over are really persuaded, especially when they look at the area’s geology,” says Guy Grant-Macpherson, EGS Energy’s Managing Director.
According to Grant-Macpherson, the company’s strength is in the combined experience of its team, which includes Roy Baria who helped set up the Rosemanowes HDR project and led the European EGS Project for 15 years. “Roy was a man with a plan. I was looking for a plan. We started lobbying government and put together a company with private funding. The idea of ‘a journey to the centre of the earth,’ [the title of the Jules Verne novel] captured people’s imaginations,” he says.
Support from individual politicians has been encouraging, but a huge question mark hangs over public sector spending. Add to this the fact that geothermal is one of the lesser known renewable energies and funding begins to look precarious. “Finance is going to be difficult – it’s a costly project,” says Macpherson-Grant. EGS Energy received £2 million of the DECC’s geothermal fund and is seeking private financing from utility and oil companies to find the £24.5 million necessary. The Eden Project geothermal project received planning permission in December 2010. Drilling is scheduled to start in summer 2011 and electricity should be produced from the second half of 2013. It is expected to produce up to 4MW of energy for use by Eden with the surplus to be sold to the National Grid.
Geothermal technology falls into the UK Government’s ‘innovative’ technology band, which means it is eligible for support in the form of Renewable Obligation Certificates (ROCs) at a rate of two ROCs per MWh generated. Heat produced from geothermal sources is also likely to be eligible for subsidies under the yet-to-be-published Renewable Heat Incentive.
EGS Energy
www.egs-energy.com
Guy Macpherson-Grant is the Managing Director and a founder shareholder of EGS Energy, based in Penzance, Cornwall. Technical Director is Roy Baria, who was a researcher at the Rosemanowes project for 14 years and subsequently Chief Scientist and project coordinator of the European EGS geothermal programme at Soultz-sous-Forêts, France until 2005.
EGS Energy has a partnership with the Eden Project, based near St Austell, for an engineered geothermal system power plant. The £25 million project received planning permission in December 2010 and drilling is expected to commence during 2011.
EGS Energy is developing a deep drilling technology in partnership with Slovakian company, Geothermal Anywhere (www.geothermalanywhere.com). The Geothermal Anywhere technology, which is also being applied in the oil and gas sectors, is based on non-contact methods of rock disintegration. The rock crushing technology, which involves bringing together an electrical discharge, pulsed plasma and a jet of water in appropriate combinations, is understood to avoid the limitations of conventional rotary drilling and is expected to be appropriate for integration into high temperature and pressure environments.
EGS Energy and Geothermal Anywhere are working together on applications for European grants under the EU’s Framework Programme 7 in the Nanosciences, Nanotechnologies, Materials and new Production Technologies Calls.
Geothermal Engineering Limited
www.geothermalengineering.co.uk
Geothermal Engineering, based in London, was founded in 2008 by MD Ryan Law, a geologist who previously worked for engineering consultancy firm Arup on geothermal energy systems. The company has a partnership with Arup.
Geothermal Engineering received a £1.5 million grant from the DECC in 2009 for the construction of a geothermal power plant in Cornwall and has raised a total of £10.5 million for that project (including the DECC funding).
The company’s Chief Technical Advisor is Tony Batchelor, who was the director of the Cornwall Hot Dry Rock geothermal energy research project between 1976 and 1991. Geothermal Engineering is understood to be raising funding of £30 million to complete the Cornwall project.
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